Process of dressing coal



April 1932- K. LEHMANN PRQCE SS 0F DRESSING COAL a Sheets-Sheet 1 FiledJuly 19. 1930 Inventor kavi ZJJZm/Qznh/ 3 Sheets-Sheet 2 Filed July 19,1930- Kar'Z LeA-mazrrw Attorney Patented p 1 ,19 2 I 1,854,659

UNITED STATES PATEN'D- om n or seen, I I V ma on naassme con IApplication me m 19, mo; sum No. 469,229, a in Germany a1, '31, ms.

The general purpose of the process of not been used for coalex ptpossibly for the dressing coal, as heretofore practised, is to articularpurpose of reducing the coal uniseparate shale and like impurities fromthe ormly to granules of a {particular size.- coal, which is done by awet ora dry process, Elastic percussion or thezresilient disinte- 6 andtdg'rade the coal according to size, crushgrating action applied inaccordance with my 55 ing alpparatus bein sometimes used as aidsinvention reduces the coal to anules or for t s purpose; on adedaccording lumps of different sizes, the sma est consistto size, by thesemethods, t e coal in the va.-' g of :Eusite, which is more or lessfriable,

fous grades is still in the main of fiPPl'OH- and the intermediate sizebeing the brittle 10 mately uniform average petrographic and vitrite.The hard, resilient duriteresiststhe 00 chemical composition. e blowsloigcest, and furnishes the largest The object of m invention istoefiect'the pieces. er the elastic percussion thethree dressing withgra 'ng of the coal according petro aphic constituents can easil besepato itidpetrographic constituents. rated y screening or by othersuita le means.

16 M an research has shown that coal, pre- The elastic percussion may beapplied by 66 viously regarded as a substantially homogesub ecting thecoal to elastic blows or taps, neous substance, consists in fact ofthree or byflin gor beatin it, asin a millwith constituent substantiallydifierent from each heaters. or example,t e coal maybe laced other,namely :-(1) Vitrite, (2) Durite, (3) in a rotating sifting drum inwhich t ereis Fusite. a shaft, rotating in the same or in the '0 po- Inaddition to purely physical difi'erences site direction, with elasticheater bars ed the chemical compositions of these constituthereto. Inmany cases it may be necesents differ substantially from each other, andsary to repeat the elastic percussive treatthe same are, accordingly,not all equally ment, in order thoroughly to separate the 25 welladapted for the same uses. Fusite, for intimately associatedpetrographic constitexample, is best adapted for powdered fuel uents ofthe raw coal. Separation of imfurnaces, and vitrite is best ada ted forcpk-. purities may precede this treatment, but it ing fusite and. duritebeing in eriorcok ng may be convenient to. first effect a prelimicoDurite is best adapted'for gas1fica-' nary separation of the petro aphicconwtion, production of oil and various chemistituents, then clean thecoal,an finall .com-

cal. rocemes. I I r plots the se aration of the trographicconelcllifl'ereiicesdin rbzgard to physigaiprtipstituent's. tle or: of ceanfcoal the elegerties ave a rea y n recogmze ere 0- tie rcussive reaent isfio course su fore, and suggestions have been made for uti-Sficieii: for alt urpose L arti ulaid- 5 lizi'ng the same for grading thecoal; It has I vantage of the process is that it can be Per.-

in fact been suggested inprint, that breaking f d h ll i 7 r I P the f 5p l r sizes m y Pesult in In regard to the separation of the fusife: gpr fi gg gg gg gg g. it'is found that from the econoltngcvpoint of sicerences no 1 0 EH 6 been made to ascertain whether this g i g a p z g :2

method would Produce useful results. I@ s g. h 1 have found thatordinary methods of disinif 1 1% by gz g m? Shown tegrating, as employedin connection with i suction gf ,thedressmgof coal,arenotefl'ectiveforsepap 5 y y g 1m 3 rating the petrographic constituents, whereasfusih .2 comp. I 1 suchseparatiori'can be efiected by subjectingsepammona m v Tests have also shown that a vltnte content the coal toelast1c percussion or to resihent disintegrdting actiom Some knownkinds-of P 'f' un 9 l p' apparatus sub'ject the-material may obtained. II I I treated elastic percussion, but these have I One method ofcarrying the invention nto e;

effect and two forms of "mills are shown in the annexed drawings, inwhich 2- Figure 1 is a flow sheet illustrating the method,

Figure 2 is a vertical sectional view of a mill, and

Fi ure 3 is a vertical section of a modified orm of mill.

The coal is fed from a hopper a to a classifying drum or vibratingscreen I), which separates it into granules of three sizes 1, 2 and 3.The coarsest coal is treated on cleaning bands 0 or by means of othersuitable appliances for separation of the coarser impurities. A breakerd is provided for elastic treatment whereby preliminary separationaccording to petrographic constitution is effected, the separation beingefiected so that the vitrite remains in the most finely divided coal,the vitrite in the middings, and the durite in the coarse coal. For thispurpose a disintegrator may, for example, be used, the coal of sizes 1and 2 being fed to the same. The coal discharged from the mill, togetherwith the coal 3 from the screen 6, passes to the screen 0, which may bea vibrating screen and separates the coal according to three sizes 4, 5and 6, which are delivered separately to three cleaning tables 9 withsuction hoods, of a known type, for separating shale,

but the most finely divided coal first passes through a pneumatic sifterf. The most finely divided clean coal 7 taken from the cleaning tablesconsists almost exclusively of vitrite, and is conveyed away for use.The two coarser fractions 8 and 9 are fed to mills h with elasticbeaters, which complete the separation according to petrographicconstitution. The mills may, for example, consist of screening drums inwhich there are shafts with elastic heaters, rotating in the samedirection as the-drums or in the opposite direction, at appropriatespeeds, the fineness of the screens depending on the petrographicstructure of the coal. The beaters may be arms elastically connected tothe .shafts. By striking the coal they separate the vitrite from thedurite, the former being discharged through the screen.v

The fine coal dust separated by the suction appliances at the variousstages, particularly the cleaning tables and mills, is practically freefrom. durite, and consists mainly of fusite, with some vitrite. It isdeposited and collected by means-of cyclone appliances 5, or in anyother convenient way. Shale and other coarser impurities coming from thecleaning bands 0 and principally from the cleaning tables 9 are led.away on line B.

Substantially complete separation of the raw coal into. its petrographicconstituents is thus effected, but in regard to detail the mode ofprocedure may be varied in many by appropriate phur to becomeconcentrated'mainly in one of the fractions, so that separation thereofmeans is facilitated. Two forms of mills have been illustrated inFigures 2 and 3 in which Figure 2 consists essentially of a sieve drum 1which surrounds a percussion device consisting of a plurality of elasticbeater bars 3. These bars are pivoted as pendulums and are secured tothe shaft 2 'of the mill by means of the circular disks 5. The drum 3receives its rotation from the driving pulley 6 and the shaft 2 receivesits rotation from the driving ulley 7 The material to be treated isplace in the mill through the entry tube 8 and enters the interior ofthe drum -1 atthe ri ht end of the drum. The material after eingtreated' leaves the drum at the left end by means of the openings 9. ,Inthis manner the coal I which is to be disintegrated will be repeatedlystruck by the bars 3 and the coal will thus be divided into its threeconstituents in that the harder material, durite, which will be largerkernels, will be forced against the sides of the drum and eventuallywill fall into the container 10. The other particles vitrite and fusitewhich will beiin the form of smaller kernels will fallcthrough the sieveand will eventually be de osited into the container 11. The fusite isseparated from the vitrite by suction so that eventually only the'vitrite will be contained in the container 11. The entire mill isdisclosed in a dust-proof casing 12. I

In Figure 3 a modified form of mill is shown which consists of an outercasing or mantle 13 which surrounds the'inner mantle 14 arranged in theform of ste s. Centrall of the mill there is arranged a s aft 15 whiccontains the beater arms 16 hav'ingattheir ends the beater 17. From thetop to the bottom the beater arms progress m'length as.

through the mill. The finely divided vitrite and fusite will be forcedthrough the sieves 18 and they will eventually fall through the outlet21. However, the extremely fine fusite may be forced by suction throughthe outlet opening 20 at the top so that in that manner 1'25 thematerial fallingthrough the outlet21 is merely vitrite. The sieves 18decrease in size from the top to the bottom but the durite which remainsin the eventually fall through the bottom into the trough through thevibration sieve 23 and the very fine fusite remaining will be forced bysuction out through the pipe 24.

I claim 1. A process of dressing coal, comprising subjecting the .coalto elastic percussion, whereby the fusite, durite and vitriteconstituents are respectively broken up into granules of differentsizes, and separating the granules of different sizes by screening.

2. A process of dressing coal, comprising subjecting the coal to wherebythe fusite, durite and vitrite constituents are respectively broken upinto granules of different sizes, separating the granules of durite andvitrite by screening, and removing the fusite by suction.

3. A process of dressing coal, comprising subjecting the coal torepeated elastic percussive treatments, whereby the, fusite, durite andvitrite constituents are respectively broken up into granules ofdiflt'erent sizes, separating the granules of durite and vitrite byscreening, and removing the fusite by suction.

4; A process of dressing coal, comprising first subjecting the coal toelastic percussive treatment for preliminary division thereof into itsfusite, durite and vitrite constituents, then separating the impuritiesfrom the coal, subjecting it to further plastic percussive treatment,whereby the said constituents are respectively broken up into granulesof different sizes, and finally separating said granules of differentsizes by screening.

5. A process of dressing coal, comprising subjecting the coal torepeated elastic percussive treatments, whereby the fusite, durite andvitrite constituents are respectively broken up into granules ofdifferent sizes, separating the granules of durite and vitrite byscreenlng; and subjecting the coal to suction at the successive stagesof treatment, whereby the fusite .is separated.

6. A process of grading coal by disintegration thereof and separation ofthe several macroscopic banded constituents, comprising in subjectingthe coal to resilient disintegrating action whereby the constituents arebroken up into granules of difi'erent sizes and separating the granulesof different sizes.

In testimony whereof, I afiix my signature.

KARL LEHMANN.

elastic percussion,

